JP2004337340A - Washing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure high detergency, reduce uneven washing and set a delivery amount of bubbles within a fixed range even if the level of an inner tub is varied and the types and the amount of detergent are changed by lifting bubbles formed from dissolved detergent solution and pouring them on the laundry in the inner tub from an upper part in a washing machine delivering the bubbles from upper part of the laundry and washing it. <P>SOLUTION: A bubble chamber is formed inside an outer tub, a power is fed to a motor 9 by an inverter 14 having switching elements 14a-14f, and a control means 16 controls conduction ratio of the switching elements 14a-14f to control the rotating speed of the motor 9. This washing machine is provided with a bubble process of driving the inner tub, and lifting and delivering the bubble formed between the inner tub and the outer tub, controls the conduction ratio of the switching elements 14a-14f based on a comparison result of an output value of a current detecting means 18 which detects a current value corresponding to the motor 9, with a current set value, controls the rotating speed of the motor and sets the delivery amount of the bubbles within the fixed range. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a washing machine that discharges foam from above laundry and performs washing.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a typical washing machine is a type in which wings called a pulsator are rotated for washing, and the configuration of this type of washing machine will be described with reference to FIG.
[0003]
As shown in FIG. 9, the outer tub 30 includes an inner tub 32 in which wings 31 are rotatably arranged at the bottom, and is suspended from a housing 34 by a suspension rod 33. The motor 35 drives the wing 31 or the inner tub 32 via the V-belt 36 and the speed reduction mechanism / clutch 37. The drain valve 38 drains the washing liquid in the inner tub 32, and the water supply valve 39 supplies water to the inner tub 32.
[0004]
A fluid balancer 40 for reducing vibration during dehydration is provided above the inner tank 32, and a lid 41 is provided above the inner tank 32. The control device 42 controls the motor 35, the drain valve 38, the water supply valve 39, and the like to sequentially control a series of steps of washing, rinsing, and dehydrating (for example, see Patent Document 1).
[0005]
The operation will be described in the above configuration. When washing is started after the laundry and a predetermined amount of detergent are put into the inner tub 32, the water supply valve 39 is controlled by the control device 42 to control the water supply valve 39 into the inner tub 32. Then, the control device 42 controls the motor 35 to drive the wing 31. With the rotation of the wings 31, the laundry in the inner tub 32 and the water are mixed, whereby the detergent gradually dissolves to form a washing liquid, which acts on the soil of the laundry.
[0006]
[Patent Document 1]
JP 2001-378326 A
[0007]
[Problems to be solved by the invention]
However, in the case of the washing machine having this configuration, the washing power is secured only by the mechanical force of washing the inner tub 32 by the wings 31, so that the laundry at the bottom of the inner tub 32 has no mechanical power. Although it is easy to transmit and high washing power is obtained, there is a problem that the washing power at the upper portion of the inner tub 32 is hardly transmitted to the laundry, so that the washing power cannot be obtained and the washing unevenness becomes large.
[0008]
The present invention solves the above-mentioned problems, and pumps foam generated from a dissolved washing liquid upward and applies it to laundry in an inner tub from above, thereby ensuring high detergency and reducing washing unevenness. Further, it is another object of the present invention to control the discharge amount of the foam to be within a certain range.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention rotatably accommodates an inner tub for storing laundry in an outer tub, forms a bubble chamber on the inner surface of the outer tub, and rotates the inner tub by an inverter having a switching element. Power is supplied to the driving means to be driven, and the control means controls the conduction ratio of the switching element to control the number of rotations of the driving means. Pumping and discharging the foam, and controlling the conduction ratio of the switching element based on the comparison result between the output value of the current detecting means for detecting the current value corresponding to the driving means and the current set value, By controlling the number of revolutions, the discharge amount of the foam is controlled to be within a certain range.
[0010]
As a result, foam is generated from the dissolved washing liquid, the generated foam is collected in the foam chamber, pumped upward, and applied to the laundry in the inner tub from above, thereby ensuring high detergency and preventing uneven washing. Further, by detecting the output value of the current detecting means, controlling the conduction ratio of the switching element based on the comparison result of the output value and the current set value, and controlling the rotation speed of the driving means, Can be controlled within a certain range, and the amount of foam discharged can be controlled optimally without being too large or too small.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
The invention according to claim 1 of the present invention provides an inner tub that stores laundry, an outer tub that rotatably stores the inner tub, a driving unit that drives the inner tub to rotate, and an inner surface of the outer tub. An inverter having a switching element for supplying power to the drive means, a current detection means for detecting a current value corresponding to the drive means, and controlling the conduction ratio of the switching element to drive the drive means. Control means for controlling the number of rotations of the means, and has a bubble stroke for pumping and discharging bubbles generated between the inner tank and the outer tank by rotationally driving the inner tank, and an output of the current detecting means. By controlling the conduction ratio of the switching element according to the result of comparison between the current value and the current setting value, and controlling the number of revolutions of the driving means, the amount of foam discharged is kept within a certain range. Bubbles were generated from the liquid and generated By collecting the water in the foam chamber and pumping it upwards and applying it to the laundry in the inner tub from above, high washing power can be secured and washing unevenness can be reduced, and the output value of the current detecting means is detected. By controlling the rotation of the inner tank while monitoring the current flowing through the driving means, and by applying a constant torque to the inner tank by making the torque of the driving means constant, variations in the water level of the inner tank, Even if the type or amount changes, the discharge amount of the foam can be kept within a certain range. As a result, it is possible to prevent the foam from overflowing due to an increase in the discharge amount of the foam, and it is possible to clean the clothes.
[0012]
According to a second aspect of the present invention, in the first aspect of the present invention, a water level detecting means for detecting a water level in the outer tub is provided, and a current set value is changed by an output signal detected by the water level detecting means. When the amount of washing water is large, the number of rotations can be reduced to avoid abnormal conditions such as foam overflowing from the outer tub. it can.
[0013]
According to a third aspect of the present invention, in the first aspect of the present invention, a bubble stroke having a plurality of set water levels is provided, and the current set value is changed according to each set water level. Yes, a washing method suitable for the set water level can be realized, and when the set water level is high, the number of revolutions can be reduced to avoid an abnormal state such as bubbles overflowing from the outer tank.
[0014]
According to a fourth aspect of the present invention, in the first aspect of the present invention, there is provided a rotational speed detecting means for detecting a rotational speed of the driving means or the inner tank, wherein an output value of the rotational speed detecting means and a predetermined rotational speed are determined. In comparison, the conduction ratio of the switching element is controlled so that the rotation speed does not exceed a predetermined rotation speed. It is possible to prevent the bubbles from overflowing due to the increased amount.
[0015]
【Example】
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0016]
As shown in FIG. 2, the outer tub 1 includes an inner tub 2 rotatably disposed inside, and wings 4 are rotatably disposed on the inner bottom of the inner tub 2 via a clutch and reduction mechanism 3. Has been established. An outer tank cover 6 is provided at the upper opening of the outer tank 1 via a packing 5, and is suspended from a housing 8 by a suspending rod 7.
[0017]
The motor (drive means) 9 is constituted by a DC brushless motor, and rotationally drives the inner tank 2 or the blade 4 via the clutch and reduction mechanism 3. The water supply valve 10 is for supplying water to the inner tub 2, the water level detecting means 11 is for detecting the water level in the outer tub 1, and the drain valve 12 is for draining the washing liquid in the outer tub 1. is there.
[0018]
As shown in FIG. 1, the motor 9 includes a stator (not shown) having a three-phase winding 13 and a rotor (not shown) having a two-pole permanent magnet disposed on a ring. , A first winding 13a, a second winding 13b, and a third winding 13c constituting the three-phase winding 13 are wound around the stator.
[0019]
The inverter 14 is configured by a switching element including a parallel circuit of a power transistor (IGBT) and a reverse conducting diode. It comprises a series circuit of the switching element 14a and the switching element 14b, a series circuit of the switching element 14c and the switching element 14d, and a series circuit of the switching element 14e and the switching element 14f, and the series circuit of the switching elements 14a to 14f is in parallel. Connected.
[0020]
Here, both ends of the series circuit of the switching elements are input terminals, a DC power supply is connected, and output terminals are respectively connected to connection points of two switching elements forming the series circuit of the switching elements. The output terminal is connected to three terminals of the three-phase winding 13, a U terminal, a V terminal, and a W terminal. The terminal and the W terminal are set to three states: positive voltage, zero voltage, and release.
[0021]
The switching elements 14a to 14f are turned on and off via a drive circuit 15, a control unit 16, a first rotor position detecting unit 17a, a second rotor position detecting unit 17b, and a third rotor position detecting unit 17c. Is controlled by The first rotor position detecting means 17a, the second rotor position detecting means 17b, and the third rotor position detecting means 17c face the permanent magnets provided on the rotor of the motor 9 at an electrical angle of 120 degrees. , Are arranged on the stator.
[0022]
As shown in FIG. 3, during the rotation of the motor 9 by one rotation, the first rotor position detecting means 17a, the second rotor position detecting means 17b, and the third rotor position detecting means 17c each have the timing shown in FIG. Thus, one pulse of a high-low signal is output. The control means 16 detects the timing of the arrow shown in the figure, that is, when any of the three rotor position detection means changes the signal from high to low and from low to high. Hereinafter, the output of the pulse signal from the rotor position detecting means means this timing.
[0023]
The first rotor position detecting means 17a, the second rotor position detecting means 17b, and the third rotor position detecting means 17c are constituted by elements for detecting the state of a magnetic field such as a Hall IC, and include a permanent magnet provided on the rotor. A high signal is output when facing the N pole surface, and a low signal is output when facing the S pole surface (or vice versa). Further, the number of revolutions of the motor 9 can be detected by the pulse period of the first rotor position detecting means 17a when the motor 9 rotates, so that the number of revolutions detecting means 17 is constituted. FIG. 3 shows an example of the on / off timing of the switching elements 14a to 14f for rotating the motor 9.
[0024]
The switching elements 14a to 14f change the on / off state based on signals from the first rotor position detecting unit 17a, the second rotor position detecting unit 17b, and the third rotor position detecting unit 17c. The U terminal, the V terminal, and the W terminal are set to three states of positive voltage, zero voltage, and release, and a current flows through the first winding 13a, the second winding 13b, and the third winding 13c to create a magnetic field, Rotate the rotor.
[0025]
The control means 16 is constituted by a microcomputer and corresponds to the output signals of the first rotor position detection means 17a, the second rotor position detection means 17b, and the third rotor position detection means 17c according to the rotation direction of the inner tank 2. The switching elements 14a to 14f are turned on and off to control the motor 9. As for the rotation speed control, the rotation speed of the motor 9 or the inner tank 2 is detected based on the pulse period of the rotation speed detecting means 17, and the rotation speed data is fed back to adjust the energization ratio of the switching elements 14a to 14f. In this way, control is performed so as to reach the set rotation speed.
[0026]
The current detecting means 18 uses a resistor in the present embodiment, and detects the input current value of the inverter 14 based on the voltage across the resistor. Reference numeral 19 denotes a commercial power supply, which is connected to the inverter 14 via a DC power supply device including a diode bridge 20, a choke coil 21, and a smoothing capacitor 22. The input setting means 23 sets a driving course and the like.
[0027]
The control means 16 controls the operations of the clutch / deceleration mechanism 3, the water supply valve 10, and the drain valve 12 via the load driving means 24, and sequentially controls a series of steps of washing, rinsing, and dewatering. However, this is an example, and the configuration of the motor 9, the configuration of the inverter 14, and the like are not limited thereto.
[0028]
On the inner surface of the outer tub 1, as shown in FIG. 4, a foam chamber 25 located above the inner bottom 1a of the outer tub 1 is formed. The outer tank cover 6 is hermetically sealed with a lid 26, and a part of the lid 26 forms a part of a circulation path 27. A bubble discharge part 28 is provided at the tip of the circulation path 27. I have. The guide plate 29 constituting the bottom surface of the bubble chamber 25 is formed so as to be curved upward in the rotation direction of the inner tank 2 during the bubble stroke. As shown in FIG. 5, the foam discharge section 28 is configured such that the foam discharge direction is the same as the rotation direction of the inner tank 2 during the bubble stroke, and the discharged foam is moved from the substantially central portion 2a of the inner tank 2 to the outer peripheral portion. It is configured to take up to 2b.
[0029]
As an example of controlling the rotational torque of the motor 9 by using a control command from the control means 16 using the inverter 14, there is a method described below. Each time a pulse signal from the motor 9 is input, a current value detected by the current detection means 18 is input to the control means 16 and this current value and a target current value (current set value, target motor torque The set rotational speed manipulated variable △ Tc for searching for the currently set rotational speed Tc from the difference (deviation) determined by the amount) and the amount of change in the current value from the time of the previous measurement. calculate.
[0030]
When a large amount of current tends to flow, the set rotation speed Tc is lowered to reduce the current value, and when a small amount of current tends to flow, the set rotation speed Tc is increased to flow the current value. Such a control rule is used. Then, feedback control is performed on the basis of the rotation speed detected by the rotation speed detecting means 17 so as to actually rotate at the set rotation speed Tc determined by the current value.
[0031]
The conduction ratio of the switching elements 14a to 14f of the inverter 14 is operated based on the difference (deviation amount) between the rotation speed Tp and the set rotation speed Tc detected by the rotation speed detecting means 17 and the amount of change in the rotation speed from the previous measurement. The operation amount ΔPa is calculated by fuzzy control or the like, and the conduction ratio is reset.
[0032]
When the rotation speed is higher than the set rotation speed, the duty ratio of the switching element is reduced to reduce the rotation speed, and when the rotation speed is lower than the set rotation speed, the duty ratio of the switching element is increased to increase the rotation speed. Control. That is, the number of revolutions is determined from the current value of the current flowing so that the target current (torque) is obtained, and the rotation control is performed so as to achieve this number of revolutions.
[0033]
In the case of a DC brushless motor, the current value flowing through the motor 9 and the torque of the motor 9 are in a proportional relationship. The higher the current value flowing through the motor 9, the higher the torque that can be obtained from the motor 9. In the washing machine having the above structure, the torque from the motor 9 can be transmitted to the inner tub 2 to rotate the inner tub 2.
[0034]
Determining the number of rotations from the value of the current flowing through the motor 9 and controlling the rotation so as to achieve the determined number of rotations means controlling the current value to be constant. That is, in this control method, controlling the total amount of the amount of washing water in the inner tub 2 and the amount of clothes at a certain number of rotations (determined by a current value) means controlling with a constant torque. That is, although the number of rotations changes, the torque by the motor 9 is controlled to be constant.
[0035]
The washing water level varies within a certain range depending on the variation of the water level detecting means 11 and the amount and type of the laundry, and when the washing water level is high, when the inner tub 2 is rotated, the foam discharge portion 28 When the amount of discharged foam is increased and the rotation speed of the inner tub 2 is kept constant, the washing water level (water level of the outer tub 1), the foam discharge amount and the motor current value (motor torque) are as shown in FIG. ). In FIG. 6A, a substantially straight line B indicates a bubble discharge amount, a substantially straight line I indicates a motor current value, P is a reference water level, P1 is an upper limit value of variation, and P2 is a lower limit value of variation.
[0036]
In addition, when the inner tank 2 is rotated, the amount of foam generated between the inner tank 2 and the outer tank 1 varies depending on the type and amount of the detergent, and the amount of foam generated is large. The figure shows that when the amount of foam discharged from the foam discharge unit 28 increases and the rotation speed of the inner tank 2 is kept constant, the amount of generated foam, the amount of foam discharged, and the motor current value (motor torque) are shown in FIG. 6 (b). In FIG. 6B, a substantially straight line B indicates a bubble discharge amount, and a substantially straight line I indicates a motor current value.
[0037]
If the discharge amount of the foam is too large, in the worst case, the foam overflows from the outer tub 1, and if the discharge amount of the foam is small, the washing performance deteriorates. From the above relationship, there is a substantially proportional relationship between the discharge amount of foam and the current value (motor torque) as shown in FIG.
[0038]
As is clear from FIG. 6, by controlling the value of the current flowing through the motor 9 to be substantially constant, even if the amount of foam generated due to variations in the washing water level or the type and amount of detergent changes, the amount of foam discharged is substantially constant. Can be kept. That is, by controlling the value of the current flowing through the motor 9 to be substantially constant, the rotation speed of the inner tub 2 decreases when the washing water level is high or when the amount of generated bubbles is large, and when the washing water level is low, When foaming is small, the number of revolutions of foam can be kept almost constant by increasing the rotation speed of the tank 2.
[0039]
By controlling the current of the motor 9 in this manner, even if the washing water level varies and the foaming due to the type and amount of the detergent changes, the foam can be prevented from overflowing from the outer tub 1, and Can be realized.
[0040]
The operation of the above configuration will be described with reference to FIGS. First, in step 51 of FIG. 7, the power switch (not shown) of the input setting means 23 is turned on. Next, in step 52, an operation course suitable for the type of laundry, the degree of dirt, etc. is selected by the input setting means 23. After that, when the start switch (not shown) is pressed in step 53, the operation starts, the amount of laundry (cloth amount) put in the inner tub 2 is determined, and the set water level is determined.
[0041]
As a method of determining the cloth amount, the motor 9 is driven to invert the wings 7 left and right, and the rotational speed when the motor 9 is turned off is detected by the rotational speed detecting means 17, and the inertial rotational speed is small. At this time, it is determined that the cloth amount is small, and conversely, when the coasting speed is large, it is determined that the cloth amount is large.
[0042]
In step 54, water supply at the set water level PS1 is started, the water supply valve 10 is turned on, and water is supplied into the inner tank 2. In step 55, water supply is continued until the water level detection means 10 detects the set water level PS1, and when the water level detection means 11 detects the set water level PS1, the process proceeds to step 56, where the water supply valve 10 is turned off and the water supply is terminated. After the water supply is completed, the washing operation is started by rotating the inner tub 2 after step 57.
[0043]
In step 57, the current set value It is determined, and control (constant torque control) is performed so that the current value of the motor 9 becomes equal to the set washing value It. Make sure that the foam can be discharged properly. This is because there is a substantially proportional relationship between the amount of foam discharge and the current value (motor torque) as shown in FIG.
[0044]
In step 58, the timer 1 for counting the total washing time is cleared, and in step 59, the timer 2 for counting the ON or OFF time when the motor 9 is turned on / off is cleared. Then, after step 60, the actual washing operation is started.
[0045]
At this time, the relationship between the rotation speed of the inner tub 2 and the current value flowing through the motor 9 and the elapsed time are shown in FIGS. That is, the motor 9 is periodically turned on to rotate the inner tub 2 to circulate the washing water to remove dirt from clothes. When the motor 9 is turned on, the motor current is increased to generate torque in the motor 9 until the motor current value It is reached, thereby increasing the rotation speed of the inner tub 2 and converging the motor current value to It. Control. At this time, the rotation speed also converges to a predetermined rotation speed (for example, 190 r / min).
[0046]
In step 60, start-up control for driving the motor 9 is performed. As a start-up control method, after the motor 9 is turned on, the conduction ratio of the switching elements 14a to 14f of the inverter 14 is gradually increased with time, and the torque of the motor 9 is increased. After startup, in steps 61 to 72, the conduction ratio of the switching elements 14a to 14f of the inverter 14 is controlled based on the motor current value detected by the current detection means 18 and the rotation speed detected by the rotation speed detection means 17, and the current value Then, feedback control is performed on both elements of the rotation speed and the rotation speed, and the inner tub 2 is controlled to rotate under a constant torque.
[0047]
Then, in step 61, the motor 9 is turned on and the inner tank 2 is rotated until the periodic on time t1 of the motor 9 elapses. When the time t1 has elapsed, the routine proceeds to step 73, where the motor 9 is stopped.
[0048]
The specific control method in steps 62 to 72 is as follows. In step 62, it is determined whether a signal from the rotation speed detecting means 17 has been input. When the signal from the rotation speed detecting means 17 is input, the process proceeds to step 63. In step 63, the current detection means 18 detects the current value Im flowing to the motor 9 at this time. Since the relationship between the current value and the motor torque is in a proportional relationship, the torque value applied to the motor 9 at this time can be estimated.
[0049]
Next, in step 64, the change amount △ Im (= Im−Imn−) between the current value Imn−1 detected by the current detection unit 18 when the signal was input from the rotation speed detection unit 17 last time and the current value Im detected this time. 1) is calculated. In step 65, the difference (deviation Ie) between the current set value It and the current value Im is calculated. In step 66, an operation amount △ Tc to be operated is calculated from the currently set rotational speed based on the deviation Ie and the change amount △ Im. In step 67, a new set rotation speed Tc is set.
[0050]
In step 68, the current rotation speed Tp is obtained from the signal detected by the rotation speed detection means 17, and in step 69, the rotation speed Tpn-1 detected when the signal was previously input from the rotation speed detection means 17 and the rotation speed detected this time. The change amount of the number Tp ΔTp (= Tp−Tpn−1) is calculated. In step 70, the difference (deviation Te) between the set rotation speed Tc and the current rotation speed Tp is calculated. In step 71, an operation amount △ Pc to be operated is calculated from the current energization ratio of the switching element based on the deviation Te and the change amount △ Tp. That is, feedback control based on the current value and feedback control based on the rotation speed are performed in combination.
[0051]
Proceeding to step 72, a new conduction ratio Pa is set based on the manipulated variable △ P1. The control is repeated until the time t1 elapses, the rotation control of the inner tub 2 is performed under a constant torque, and the inner tub 2 is rotated at a high speed, so that a large amount of air is supplied to the washing liquid between the inner tub 2 and the outer tub 1. To mix the washing liquid and air to generate a large amount of foam. Then, since a large amount of generated foam has a low specific gravity, it moves to the upper part of the washing liquid, and vigorously enters the foam chamber 25 while rotating inside the outer tub 1.
[0052]
The foam that has entered the foam chamber 25 is pumped upward by converting the velocity component thereof from the horizontal direction to the vertical direction along the guide plate 31, and is washed from the foam discharge section 28 through the circulation path 27 into the washing in the inner tub 2. A bubble washing process is performed in which the foam is discharged from above the object.
[0053]
If this operation is performed continuously, the winding temperature of the motor 9 rises excessively, so that it is necessary to insert a motor-off period for a certain time. Therefore, the process proceeds to step 73, and in steps 73 to 75, the motor 9 is turned off only for the period of time t2. The periodic intermittent operation of turning on the motor t1 for the time t1 and turning off the motor 9 for the time t2 is repeated until the washing time tsen elapses. Assuming that the washing time has elapsed when the time tsen has elapsed, the process proceeds to the next step.
[0054]
At this time, the rotation speed of the inner tub 2 is changed within a range of the rotation speed lower than the preset upper limit of the rotation speed of the inner tub 2 (for example, 200 r / min). Even when the load torque is extremely small, it is possible to prevent the discharge amount of the foam from being too large or causing a dangerous state without the rotational speed of the inner tank 2 being too high.
[0055]
As described above, according to the present embodiment, the foam chamber 25 is formed on the inner surface of the outer tub 1, and the inner tub 2 is rotationally driven to pump and discharge bubbles generated between the inner tub 2 and the outer tub 1. While having a bubble stroke, the conduction ratio of the switching elements 14a to 14f is controlled based on the comparison result between the output value of the current detection means 18 for detecting the current value corresponding to the motor 9 and the current set value, and the rotation speed of the motor 9 is reduced. By controlling, the discharge amount of foam was made to be within a certain range, so that foam was generated from the dissolved washing liquid, the generated foam was collected in the foam chamber 25 and pumped upward, and the laundry in the inner tub 2 was washed. The surface of the laundry or the laundry can be passed through the object from above, so that a high detergency can be ensured and washing unevenness can be reduced. Further, the output value of the current detecting means 18 is detected, the conduction ratio of the switching elements 14a to 14f is controlled based on the result of comparison between the output value and the current set value, and the rotation speed of the motor 9 is controlled, thereby discharging bubbles. Since the amount can be within a certain range, it is possible to perform optimal control without causing the amount of foam to be discharged so much that the foam overflows from the outer tub 1 or, on the contrary, almost no foam is discharged. In addition, since the volume of the washing liquid is increased by foaming the washing liquid, the detergent component can be made to act on the soil of the laundry with a small amount of the washing liquid.
[0056]
In addition, since the current set value is changed by an output signal detected by the water level detecting means 11, a washing method suitable for the amount of washing water can be realized, and when the amount of washing water is large, the number of revolutions is reduced. Abnormal conditions such as bubbles overflowing from the outer tank 1 can be avoided.
[0057]
In addition, a bubble stroke having a plurality of set water levels is provided, and the current set value is changed according to each set water level, so that a washing method suitable for the set water level can be realized, and the set water level is high. In some cases, the number of rotations can be reduced to avoid an abnormal state such as bubbles overflowing from the outer tank 1.
[0058]
In addition, the output value of the rotation speed detecting means 17 is compared with a predetermined rotation speed, and the conduction ratio of the switching elements 14a to 14f is controlled so as not to exceed the predetermined rotation speed. It is possible to prevent a dangerous state due to rising too much, and also to prevent the bubbles from overflowing due to an increase in the discharge amount of the bubbles.
[0059]
In the present embodiment, the motor 9 is constituted by a DC brushless motor, but this is an example, and the present invention is not limited to this.
[0060]
Further, in the present embodiment, the detergent is dissolved at the same time as the inner tank 2 rotates during the foaming process. However, the detergent may be dissolved before the foaming process, and the detergent may be dissolved in advance.
[0061]
Further, in the present embodiment, the periodic intermittent operation of the motor 9 for the time t1 on and the time t2 off is repeated until the washing time tsen elapses. It may be performed only once without repeating on and off.
[0062]
In the foaming process, not only foam but also a mixture of foam and washing liquid may be discharged.
[0063]
【The invention's effect】
As described above, according to the first aspect of the present invention, the inner tub for storing the laundry is rotatably accommodated in the outer tub, the foam chamber is formed on the inner surface of the outer tub, and the switching element is provided. An inverter having a configuration in which power is supplied to a driving unit that rotationally drives the inner tank, and a control unit controls the conduction ratio of the switching element to control the number of rotations of the driving unit. It has a foaming stroke for pumping and discharging bubbles generated between the outer tank and a conduction ratio of the switching element according to a result of comparison between an output value of a current detecting means for detecting a current value corresponding to the driving means and a current set value. By controlling the number of rotations of the driving means, the discharge amount of foam was made to be within a certain range, so that foam was generated from the dissolved washing liquid, and the generated foam was collected in the foam chamber and upward. Pump the water and wash the laundry in the inner tub from above. As a result, high washing power can be ensured and washing unevenness can be reduced. Therefore, almost the same amount of foam can be discharged even when the water level of the inner tank varies and the type and amount of the detergent are changed. As a result, it is possible to prevent the foam from overflowing due to an increase in the amount of foam to be discharged, and it is possible to clean the clothes.
[Brief description of the drawings]
FIG. 1 is a circuit diagram of a washing machine according to an embodiment of the present invention, which is partly blocked.
FIG. 2 is a longitudinal sectional view of the washing machine.
FIG. 3 is an operation timing chart of the inverter of the washing machine.
FIG. 4 is a perspective view of the outer tub of the washing machine with a part cut away.
FIG. 5 is a partially cutaway perspective view of the washing machine.
FIG. 6 (a) is a characteristic diagram showing a relationship between a washing water level, a foam discharge amount, and a motor current value of the washing machine.
(B) Relationship between the foaming of the washing machine, the foam discharge amount, and the motor current value
(C) Relational characteristic diagram between the motor current value and the foam discharge amount of the washing machine
FIG. 7 is an operation flowchart of a main part of the washing machine.
FIG. 8 is an operation timing chart of main parts of the washing machine.
FIG. 9 is a longitudinal sectional view of a conventional washing machine.
[Explanation of symbols]
1 outer tank
2 inner tank
9 Motor (drive means)
14 Inverter
14a-14f switching element
16 control means
18 Current detection means
25 foam room

Claims (4)

An inner tub for storing laundry, an outer tub for rotatably storing the inner tub, a driving unit for rotating the inner tub, a foam chamber formed on an inner surface of the outer tub, and a switching element. An inverter for supplying power to the drive unit; a current detection unit for detecting a current value corresponding to the drive unit; and a control unit for controlling a conduction ratio of the switching element and controlling a rotation speed of the drive unit. Has a foaming stroke for rotating and driving the inner tank and pumping and discharging bubbles generated between the inner tank and the outer tank, and a switching element based on a comparison result between an output value of the current detecting means and a current set value. A washing machine in which the discharge ratio of foam is controlled to be within a certain range by controlling the conduction ratio of the driving means and controlling the rotation speed of the driving means. The washing machine according to claim 1, further comprising a water level detecting means for detecting a water level in the outer tub, wherein the current set value is changed by an output signal detected by the water level detecting means. The washing machine according to claim 1, further comprising a foaming stroke having a plurality of set water levels, wherein the current set value is changed according to each set water level. A rotational speed detecting means for detecting a rotational speed of the driving means or the inner tank; comparing an output value of the rotational speed detecting means with a predetermined rotational speed; controlling a conduction ratio of the switching element so as not to exceed the predetermined rotational speed; The washing machine according to claim 1, wherein the washing machine is operated.

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